Thanks for posting here in the Google Nest Community and sorry for the late response.
I know how it feels when something isn’t working as it should, so let’s get this resolved. A few things: Which Nest speaker and Chromecast device? Was this feature working before? What is the make and model of your TV?
Looking forward to your response.
Thanks for keeping us in the loop and happy to hear that this has been sorted out. Give us a shout if something comes up — you know where to find us. For your request. I'd suggest you submit feedback about it, here's how.
Let us know if you have other questions and concerns otherwise, we will be locking this thread after 24 hours.